Prep time: 45 minutes
Total time: 1 hour 20 minutes
4 medium beets (about 2 pounds)
6 tablespoons olive oil
kosher salt and freshly ground black pepper, to taste
2 tablespoons unsalted butter
8 ounces crimini mushrooms, thinly sliced
3 sprigs thyme
1 medium yellow onion, diced
juice of 1 lemon
3/4 cup green lentils
1/2 cup bulgur wheat
1/2 cup toasted cashews, ground into a powder
1 cup toasted pepitas, ground into a powder
1 1/2 tablespoons xanthan gum
12 potato rolls, halved
1 cup Greek yogurt
1 tablespoon sumac
2 avocados, peeled, pitted and thinly sliced
1. Heat oven to 425°F|220°C. Rub beets with 2 tablespoons of olive oil and salt and place in a small baking dish. Cover tightly with aluminum foil and roast until fork tender, about 1 hour. Remove from the oven and let cool. When the beets are cool enough to handle, peel the skin and cut into pieces.
2. Meanwhile, melt the butter in a medium skillet over medium-high heat. Add the mushrooms, thyme, and onion and cook, stirring occasionally, until lightly caramelized, about 12 minutes. Deglaze the skillet with the lemon juice and scrap the browned bits from the bottom of the pan. Transfer the mixture to a large bowl.
3. In a medium saucepan, bring 3 cups of water to a boil. Add the lentils and cook until tender with a slight bite, about 20 minutes. Drain and add them to the bowl with the mushrooms.
4. In a small saucepan, bring 1/2 cup water to a boil. Add the bulgur, cover, and remove from the heat. Let the bulgur sit for 10 minutes before transferring it to the bowl with the mushrooms and lentils and mix well to combine.
5. In a food processor, purée the beets with half of the mushroom mixture until it forms a paste. Transfer it back to the bowl with the reserved mushroom mixture and add in the pepitas, cashews, xanthan gum, salt, and pepper.
6. Form the mixture into 12 patties. Heat the 2 tablespoons of oil in a large cast iron skillet over medium. Working in batches, cook the patties, turning once, until lightly golden on each side, about 6 to 8 minutes. Transfer to a plate and keep warm.
7. Toast the inside of each bun until golden, about 2 minutes. Transfer to a plate with the patties.
8. Mix the yogurt with the sumac and season with salt and pepper.
9. To serve, place a patty on each bottom half of roll. Toss the lettuce with the remaining 2 tablespoons of oil plus salt and pepper. Top the patty with lettuce and a few slices of avocado. Place a doll of yogurt on top as well as the top half of the bun.